feat(companies): add admin jobs and applications list endpoints

- Add AdminJobRow and AdminApplicationRow response structs
- Implement GET /api/admin/jobs with company join and applications count
- Implement GET /api/admin/applications with applicant and job details
- Gateway routing update will follow

apps/companies/src/handlers/admin.rs

@@ -6,6 +6,7 @@ use axum::{
     routing::{get, patch},
     Json, Router,
 };
+use chrono::{DateTime, Utc};
 use contracts::auth_middleware::AuthUser;
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
@@ -17,6 +18,8 @@ pub fn router() -> Router<AppState> {
         .route("/{id}/approve", patch(approve_company))
         .route("/{id}/reject", patch(reject_company))
         .route("/{id}/suspend", patch(suspend_company))
+        .route("/jobs", get(list_jobs))
+        .route("/applications", get(list_applications))
 }
 
 #[derive(Deserialize)]
@@ -69,6 +72,43 @@ pub struct ApproveRejectRequest {
     pub reason: Option<String>,
 }
 
+#[derive(Serialize)]
+pub struct AdminJobRow {
+    pub id: Uuid,
+    pub title: String,
+    pub description: Option<String>,
+    pub company_id: Uuid,
+    pub company_name: String,
+    pub location: Option<String>,
+    pub job_type: Option<String>,
+    pub salary_min: Option<i32>,
+    pub salary_max: Option<i32>,
+    pub status: String,
+    pub is_featured: bool,
+    pub applications_count: i64,
+    pub posted_at: Option<DateTime<Utc>>,
+    pub expires_at: Option<DateTime<Utc>>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+#[derive(Serialize)]
+pub struct AdminApplicationRow {
+    pub id: Uuid,
+    pub job_id: Uuid,
+    pub job_title: String,
+    pub company_id: Uuid,
+    pub company_name: String,
+    pub applicant_id: Uuid,
+    pub applicant_name: String,
+    pub applicant_email: String,
+    pub status: String,
+    pub cover_letter: Option<String>,
+    pub resume_url: Option<String>,
+    pub applied_at: DateTime<Utc>,
+    pub created_at: DateTime<Utc>,
+}
+
 async fn list_companies(
     _auth: AuthUser,
     State(state): State<AppState>,
@@ -245,3 +285,70 @@ async fn suspend_company(
         "message": "Company suspended"
     })))
 }
+
+async fn list_jobs(
+    _auth: AuthUser,
+    State(state): State<AppState>,
+    Query(q): Query<ListQuery>,
+) -> Result<impl IntoResponse, (StatusCode, String)> {
+    let search = q.q.as_deref().unwrap_or_default().to_lowercase();
+
+    let jobs = sqlx::query_as!(
+        AdminJobRow,
+        r#"
+            SELECT 
+                j.id, j.title, j.description, j.company_id, cp.company_name,
+                j.location, j.job_type, j.salary_min, j.salary_max,
+                j.status, j.is_featured,
+                COUNT(a.id) AS "applications_count!",
+                j.posted_at, j.expires_at,
+                j.created_at, j.updated_at
+            FROM jobs j
+            JOIN company_profiles cp ON j.company_id = cp.id
+            LEFT JOIN applications a ON a.job_id = j.id
+            WHERE ($1 = '' OR LOWER(j.title) LIKE '%' || $1 || '%')
+            GROUP BY j.id, cp.company_name
+            ORDER BY j.created_at DESC
+            LIMIT 100
+        "#,
+        search
+    )
+    .fetch_all(&state.pool)
+    .await
+    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, format!("DB error: {e}")))?;
+
+    Ok(Json(jobs))
+}
+
+async fn list_applications(
+    _auth: AuthUser,
+    State(state): State<AppState>,
+    Query(q): Query<ListQuery>,
+) -> Result<impl IntoResponse, (StatusCode, String)> {
+    let search = q.q.as_deref().unwrap_or_default().to_lowercase();
+
+    let applications = sqlx::query_as!(
+        AdminApplicationRow,
+        r#"
+            SELECT 
+                a.id, a.job_id, j.title AS "job_title!", a.company_id, cp.company_name,
+                a.user_id AS "applicant_id!", COALESCE(u.first_name, '') || ' ' || COALESCE(u.last_name, '') AS "applicant_name!",
+                u.email AS "applicant_email!",
+                a.status, a.cover_letter, a.resume_url,
+                a.applied_at, a.created_at
+            FROM applications a
+            JOIN jobs j ON a.job_id = j.id
+            JOIN company_profiles cp ON j.company_id = cp.id
+            JOIN users u ON a.user_id = u.id
+            WHERE ($1 = '' OR LOWER(j.title) LIKE '%' || $1 || '%' OR LOWER(u.first_name) LIKE '%' || $1 || '%' OR LOWER(u.last_name) LIKE '%' || $1 || '%')
+            ORDER BY a.applied_at DESC
+            LIMIT 100
+        "#,
+        search
+    )
+    .fetch_all(&state.pool)
+    .await
+    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, format!("DB error: {e}")))?;
+
+    Ok(Json(applications))
+}